Create sequence belong group data.

 Hi all,

   I created report with data from sql command. I can get full of data and show them to this report. But I want show sequence per line (record) in report, it look like:

   --------

   Group A

   --------

   Seq    |    Name

   -------------------

   1        |    Butty

   2        |    Jack

   --------

   Group B

   --------

   Seq    |    Name

   -------------------

   1        |    Daisy

   2        |    Mary

   Sequence was reset belong group. How can I create this sequence ?

   Thanks !